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<div class="titlepage"><div><div><h5 class="title">
<a name="beast.ref.boost__beast__websocket__stream.async_close"></a><a class="link" href="async_close.html" title="websocket::stream::async_close">websocket::stream::async_close</a>
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<p>
          <a class="indexterm" name="idm59638"></a>
        </p>
<p>
          Send a websocket close control frame asynchronously.
        </p>
<h6>
<a name="beast.ref.boost__beast__websocket__stream.async_close.h0"></a>
          <span class="phrase"><a name="beast.ref.boost__beast__websocket__stream.async_close.synopsis"></a></span><a class="link" href="async_close.html#beast.ref.boost__beast__websocket__stream.async_close.synopsis">Synopsis</a>
        </h6>
<pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">class</span> <span class="identifier">CloseHandler</span> <span class="special">=</span> <span class="identifier">net</span><span class="special">::</span><span class="identifier">default_completion_token_t</span><span class="special">&lt;</span><a class="link" href="executor_type.html" title="websocket::stream::executor_type">executor_type</a><span class="special">&gt;&gt;</span>
<a href="../../../../../../../doc/html/boost_asio/reference/asynchronous_operations.html#boost_asio.reference.asynchronous_operations.automatic_deduction_of_initiating_function_return_type" target="_top"><span class="emphasis"><em>DEDUCED</em></span></a>
<span class="identifier">async_close</span><span class="special">(</span>
    <span class="identifier">close_reason</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">cr</span><span class="special">,</span>
    <span class="identifier">CloseHandler</span><span class="special">&amp;&amp;</span> <span class="identifier">handler</span> <span class="special">=</span> <span class="identifier">net</span><span class="special">::</span><span class="identifier">default_completion_token_t</span><span class="special">&lt;</span> <a class="link" href="executor_type.html" title="websocket::stream::executor_type">executor_type</a> <span class="special">&gt;{});</span>
</pre>
<h6>
<a name="beast.ref.boost__beast__websocket__stream.async_close.h1"></a>
          <span class="phrase"><a name="beast.ref.boost__beast__websocket__stream.async_close.description"></a></span><a class="link" href="async_close.html#beast.ref.boost__beast__websocket__stream.async_close.description">Description</a>
        </h6>
<p>
          This function is used to asynchronously send a <a href="https://tools.ietf.org/html/rfc6455#section-5.5.1" target="_top">close
          frame</a>, which begins the websocket closing handshake. The session
          ends when both ends of the connection have sent and received a close frame.
          This call always returns immediately. The asynchronous operation will continue
          until one of the following conditions is true:
        </p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
              The close frame finishes sending.
            </li>
<li class="listitem">
              An error occurs.
            </li>
</ul></div>
<p>
          The algorithm, known as a <span class="emphasis"><em>composed asynchronous operation</em></span>,
          is implemented in terms of calls to the next layer's <code class="computeroutput"><span class="identifier">async_write_some</span></code>
          function. No other operations except for message reading operations should
          be initiated on the stream after a close operation is started. After beginning
          the closing handshake, the program should not write further message data,
          pings, or pongs. Instead, the program should continue reading message data
          until an error occurs. A read returning <a class="link" href="../boost__beast__websocket__error.html" title="websocket::error"><code class="computeroutput"><span class="identifier">error</span><span class="special">::</span><span class="identifier">closed</span></code></a> indicates a successful
          connection closure.
        </p>
<h6>
<a name="beast.ref.boost__beast__websocket__stream.async_close.h2"></a>
          <span class="phrase"><a name="beast.ref.boost__beast__websocket__stream.async_close.parameters"></a></span><a class="link" href="async_close.html#beast.ref.boost__beast__websocket__stream.async_close.parameters">Parameters</a>
        </h6>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead><tr>
<th>
                  <p>
                    Name
                  </p>
                </th>
<th>
                  <p>
                    Description
                  </p>
                </th>
</tr></thead>
<tbody>
<tr>
<td>
                  <p>
                    <code class="computeroutput"><span class="identifier">cr</span></code>
                  </p>
                </td>
<td>
                  <p>
                    The reason for the close. If the close reason specifies a close
                    code other than beast::websocket::close_code::none, the close
                    frame is sent with the close code and optional reason string.
                    Otherwise, the close frame is sent with no payload.
                  </p>
                </td>
</tr>
<tr>
<td>
                  <p>
                    <code class="computeroutput"><span class="identifier">handler</span></code>
                  </p>
                </td>
<td>
                  <p>
                    The completion handler to invoke when the operation completes.
                    The implementation takes ownership of the handler by performing
                    a decay-copy. The equivalent function signature of the handler
                    must be:
                  </p>
<pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="keyword">void</span> <span class="identifier">handler</span><span class="special">(</span>
    <span class="identifier">error_code</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">ec</span>     <span class="comment">// Result of operation</span>
<span class="special">);</span>
</pre>
                  <p>
                    Regardless of whether the asynchronous operation completes immediately
                    or not, the handler will not be invoked from within this function.
                    Invocation of the handler will be performed in a manner equivalent
                    to using <code class="computeroutput"><span class="identifier">net</span><span class="special">::</span><span class="identifier">post</span></code>.
                  </p>
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<h6>
<a name="beast.ref.boost__beast__websocket__stream.async_close.h3"></a>
          <span class="phrase"><a name="beast.ref.boost__beast__websocket__stream.async_close.see_also"></a></span><a class="link" href="async_close.html#beast.ref.boost__beast__websocket__stream.async_close.see_also">See
          Also</a>
        </h6>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">
              <a href="https://tools.ietf.org/html/rfc6455#section-7.1.2" target="_top">Websocket
              Closing Handshake (RFC6455)</a>
            </li></ul></div>
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        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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